Wrapping uniformly pitched windings on a strand



A. HEINZ 3,328,945

WRAPPING UNIFORMLY PITCHED WINDINGS ON A STRAND July 4, 1967 3 Sheets-Sheet 1 Filed Sept. 23, 1964 INVENTOR ATTORNEY y 4, 1967 A. HEINZ 3,328,945

WRAPPING UNIFORMLY PITCHED WINDINC'S ON A STRAND Filed Sept 23, 1964 3 Sheets-Sheet E United States Patent 3,328,945 WRAPPING UNIFORMLY PITCHED WINDINGS ON A STRAND Alfred Heinz, Raritan Township, Hunterdon County, N.J.,

assignor to Western Electric Company Incorporated,

New York, N.Y., a corporation of New York Filed Sept. 23, 1964, Ser. No. 398,556 8 Claims. (Cl. 576) This invention relates to apparatus for winding a strand onto an elongated member, and more particularly, to apparatus for controlling the pitch of coils of tape wrapped around an advancing wire.

In manufacturing operations, it is often necessary to accurately control the relative position of various elements. When the elements are applied to a member in rapid succession and are positioned in closely spaced relationship, problems inherent in visually performed position sensing operations become critical and render necessary the use of high speed sensing facilities.

More particularly, in the manufacture of transparent ribbon cable used in permanent magnet memory array devices, numerous pairs (45 pairs, for example) of generally parallel, opaque conductors, such as wires, are embedded in laminated polyethylene sheets. The wire of one pair may be a twistor wire having magnetic twistor tape coiled or helically wrapped thereon. The memory properties of the array devices are dependent upon maintenance of a predetermined spacing or pitch between adjacent coils of the helically wrapped tape. Because the pitch of the coils is small, and because relatively high wrapping speeds are employed, visual inspection of the spacing of the coils is ineffective to insure conformity of the twistor Wire with manufacturing specifications.

It is an object of the present invention to provide new and improved apparatus for winding a strand onto an elongated member.

Another object of the present invention resides in the provision of facilities for controlling the pitch of coils of tape wrapped around an advancing wire.

Still another object of the present invention resides in the provision of facilities for illuminating an elongated member having coils of strand thereon to project light beams from the coils through a mask for sensing the spacing of coils.

A further object of the present invention is to provide a mask having a pair of spaced apertures for successively passing bands of light projected from adjacent coils wrapped on an elongated member.

A still further object of the present invention resides in the provision of facilities for advancing a carrier wire relative to coil wrapping head, including instrumentalities responsive to the pitch of wrapped coils for controlling the relative speed of the advancing facilities and the wrapping head and thereby control the pitch of the coils.

A still further object of the present invention resides in the provision of masking facilities having a pair of apertures spaced along a given direction of advancement of a wire, in conjunction with facilities for illuminating the wire to reflect light from adjacent coils of ribbon wrapped around the wire through the apertures for controlling the pitch of the coils.

With these and other objects in view, the present invention contemplates provision of facilities for advancing an elongated member, such as a carrier wire, at a selected rate along a path extending past a wrapping head which wraps a strand, such as a tape onto the advancing carrier wire to form coils having a nominal pitch which is proportional to the selected rate of advancement. Adjacent coils of the tape are illuminated to produce bands of light having a spacing indicative of the pitch of the adja- 3,328,945 Patented July 4, 1967 cent coils. Bands of light produced by the illumination of adjacent coils having an undesired pitch, pass in succession through apertures provided in a mask to successlvely render photoelectric sensing facilities effective to generate an error signal indicative of the difference between the nominal pitch and the undesired pitch. Control instrumentalities are responsive to the error signal for regulating the relative speeds of the advancing facilities and the wrapping head to form the coils having the nominal pitch.

These and other objects of the present invention will become apparent upon reference to the following description and to the accompanying drawings illustrating a preferred embodiment thereof in which:

FIG. 1 is a schematic view of an apparatus constructed in accordance with the principles of the present invention for wrapping coils of strand, such as tape, along an elongated member, such as a carrier wire, illustrating a source of illumination for reflecting a light beam from each of the coils wrapped on the carrierwire;

FIG. 2 is an enlarged, partially sectioned, elevational view of the apparatus shown in FIG. 1, illustrating light beams reflected from adjacent coils having a nominal pitch;

FIG. 3 is an enlarged, partially sectioned, elevational view similar to FIG. 2 showing light beams reflected from adjacent coils having an unacceptable pitch;

FIG. 4 is a plan view taken along line 44 of FIG. 2 showing a mask which is effective to successively pass the light beams reflected from the adjacent coils having the unacceptable pitch;

FIG. 5 is a schematic diagram of a circuit including a pair of photosensitive elements which respond to the successive light beams passed through the mask for rendering a monitoring circuit effective to generate an error signal which initiates adjustment of the rate of advancement of the carrier wire;

FIG. 6 is a perspective view of a permanent magnet memory array utilizing the carrier wire having the coils of tape wrapped thereon.

Referring now to the drawings, there is shown in FIGS. 1 and 2 an article 10 including a member, such as an elongated electrical conductor or carrier wire 11, provided with coils 12-12 of strand 14 wrapped thereon. The article 10 may be a twistor wire which is used in a twistor or ribbon type cable-of a permanent magnet matrix memory device 17 shown in FIG. 6. The carrier wire 11 may be a 3 mil copper wire, for example, and the strand 14 may be a fiat, magnetic twistor tape wrapped helically onto the carrier wire 11 with a given or nominal pitch 18.

Referring in general to the apparatus shown in FIG. 1, a supply stand 21 is shown for feeding the carrier wire 11 relative to a wrapping device 22 which wraps the spaced coils 1212 of the twistor tape 14 onto the advancing carrier wire 11 at a given rate to form the twistor wire 10. A take-up mechanism including a capstan 23 is provided for taking up the twistor wire 10 at a nominal rate of advancement which is designed to render the wrapping device 22, operating at a given rate, effective to provide the nominal pitch 18 between the coils 1212 of twistor tape.

An optical sensing unit 25 is provided for monitoring the pitch 18 of the coils 12-12 and for applying input signals 26 and 27 to a monitoring circuit 28 which controls the rate of advancement of the carrier wire 11 relative to the wrapping mechanism 22. The optical sensing unit 25 includes a light source 31 for illuminating the twistor wire 10 so that a light beam 32 is reflected from each of the coils 12-12 of the twistor tape. Referring to FIG. 2, when the nominal pitch 18 is provided between a leading coil 36 and a subsequent coil 38 of the l.) coils 12-12, first and second light beams 34 and 37 are reflected simultaneously from the respective coils 36 and 38.

A masking facility 41 (sees also FIG. 4) is provided with apertures 42 and 43 for simultaneously passing the respective light beams 34 and 37 reflected from the respective adjacent coils 36 and 38 so that simultaneous light pulses 46 and 47 are applied to respective photosensitive detectors 48 and 49. The simultaneously applied pulses 46 and 47 render the respective detectors 48 and 49 effective to generate the respective signals 26 and 27 in the form of respective simultaneous signals 44 and 45 which cause the monitoring circuit 28 to produce a zero output, indicating that the rate of advancement of the carrier wire 11 past the wrapping mechanism 22 is effective to produce the nominal pitch 18.

However, when the coils 12-12 are spaced incorrectly, as illustrated in FIG. 3 wherein the adjacent coils 51 and 52 have an unacceptable pitch 53 which deviates from the nominal pitch 18, light beams 54 and 55 reflected from the coils 51 and 52 will be spaced further apart than the apertures 42 and 43 of the mask 41. Accordingly, light pulses 58 and 59, representing the maximum amount of light passed by the respective apertures 42 and 43 from the coils 51 and 52, will be spaced by an interval of time. The interval between passage of the successive beams 54 and 55 through the respective apertures 42 and 43 is proportional to the amount that the pitch 53 varies from the nominal pitch 18. The photosensitive detectors 48 and 49 generate the signals 26 and 27 in the form of respective signals 56 and 57 having the peak values thereof spaced in time by an amount indicative of the error of the pitch 53. The signals 56 and 57 cause the monitoring circuit 28 to generate an error signal 61 having a value indicative of the error of the pitch 53 and a sign indicative of the direction of the error relative to the nominal pitch 18.

Referring to FIGS. 1 and 5, a capstan control circuit 60 is responsive to the error signal 61 for selectively adjusting the speed of the capstan 23 to regulate the rate of carrier wire advancement, and thereby render the wrapping mechanism 22 effective to provide the nominal pitch 18 between the coils 12-12 of the tape 14 wrapped onto the carrier wire 11.

The significance of providing the nominal pitch 18 between the coils 12-12 may be appreciated upon considering the structural elements of the twistor matrix memory device 17 shown in FIG. 6. The twistor matrix memory device 17 may be of the general type described in an article entitled A Twistor Matrix Memory for Semipermanent Information by Duncan H. Looney, published in the Proceedings Western Joint Computer Conference, 1959. Referring to FIG. 6, there is shown an embodiment of the twistor matrix memory device 17 designed for computers which require random access to stored information that is changed very infrequently. The device 17 shown in FIG. 6 includes permanent magnets 62-62 arranged in a pattern on cards 63-63 for storing the information. The presence or absence of one of the permanent magnets 62 is sensed nondestructively by one of the twistor wires 10-10 which is wrapped with the magnetic twistor tape 14 adjacent to the location of the permanent magnets 62. A stored word is read by a linear selection system 66 using a biased core access switch.

As noted in the article, a number of factors must be considered in the design of the twistor matrix memory 17. One factor is that the permanent magnets 62-62 must be registered accurately with bit locations 67 defined by the coils 12-12 on the twistor wires 10-10 and elongated word solenoids 68 extending perpendicular to the twistor wires 10-10. Because the permanent magnets 62-62 are minute and the twistor wires 10-10 are fine, it may be appreciated that the pitch of the coils 12-12 is critical to such accurate registration of the permanent magnets 62-62 and the bit locations 67.

Referring now in detail to FIG. 1, the supply stand 21 is shown including a support 75 which mounts a carrier wire supply reel 76 for rotation on a horizontal axis 77. The carrier wire 11 pays out from the supply reel 76 and advances past the wrapping device 22 to receive the coils 12-12 of the twistor tape 14. The twistor wire 10,

" formed by the carrier wire 11 wrapped with the coils 12-12 of the twistor tape 14, extends around the capstan 23 and onto a driven take-up reel 79. The capstan 23 is driven by a motor 81 through an electromagnetic clutch 82 to provide a variable speed drive for the twistor wire 10. In the normal operation of the clutch 82, the capstan control circuit 60 renders the clutch 82 effective to provide a selected amount of coupling between the motor 81 and the capstan 23 so that the twistor wire 10 is advanced from the wrapping device 22 at the nominal rate. The capstan control circuit 60 is adapted to increase or decrease the coupling provided by the clutch 82 so that increased or decreased rates of advancement of the twistor wire 10 may be provided.

The wrapping device 22 may be constructed according to standard specifications and is provided with a serving head 91 which rotates at a fixed rate around the advancing carrier wire 11. A twistor tape supply 92 on the serving head 91 pays out the twistor tape 14 as the serving head rotates, so that the coils 12-12 of the twistor tape are wrapped onto the carrier wire 11. Because the rate of rotation of the serving head 91 is fixed, the pitch 18 between adjacent coils 12-12 of the twistor tape 14 is dependent upon the rate of advancement of the carrier wire 11 through the serving head 91. It may be understood that with the clutch 82 adjusted to advance the twistor wire 10 at the nominal rate, the pitch 18 of the coils 12-12 will be the desired value shown in FIG. 2. If the rate of advancement exceeds the given rate, the pitch of the coils 12-12 will be the unacceptable pitch 53 (FIG. 3) which exceeds the desired pitch 18 (FIG. 2), whereas if the rate of advancement is less than the given rate, the pitch of the coils 12-12 will be less than the desired pitch 18.

The optical sensing unit 25 is mounted adjacent to the path of advancement of the twistor wire 10 to monitor the pitch of the coils 12-12. Referring to FIG. 2, the optical sensing unit 25 is shown including the light source 31 mounted within a housing 101 for projecting a beam 102 of light through a collimating lens 103. The beam 102 of light is reflected downwardly by a partial mirror 107 mounted above and at a 45 angle with respect to the path of advancement of the twistor wire 10. The light beam 102 is transmitted through a lens 108 and illuminates a section 109 of the carrier wire and the pair of adjacent coils 12-12, such as the coils 36 and 38, of the twistor tape 10.

Portions of the light beam 102 are reflected by the illuminated section 109 of the carrier wire 11 and by the adjacent coils 36 and 38 of the tape. The light-reflecting properties of the coils 36 and 38 differ from that of the carrier wire 11; hence, the beams 34 and 37 of light reflected from the respective coils 36 and 38 are visually and optically distinguishable from what may be termed background light reflected by the carrier wire 11. The beams 34 and 37 of light reflected from the respective coils 36 and 38 are reflected and projected substantially vertically through the partial mirror 107 toward the mask 41.

The mask 41 is shown in detail in FIGS. 2 and 4 including an opaque disk 110 mounted horizontally in the upper end 111 of a vertical section 112 of the housing 101. The disk 110 is oriented around a vertical axis 114 so that the apertures 42 and 43 are spaced by a distance 117 (which may span two adjacent coils or a series of coils) (FIG. 4) extending in a direction parallel to the path of the twistor wire 10. The distance 117 formula:

is determined by the distance 117=kms where:

k=the number of coils 12-12 of twister tape 14 within the optical field,

m=the optical magnification of the system (lens 108 in above example), and

s=the nominal pitch 18 between the coils 1212.

38 advance (to the right as viewed in FIG. 2) into vertical alignment with the vertical section 112 of the housing 101. As the coils 36 and 38 so advance, the reflected light beams 34 and 37 advance to the right and initially impinge upon respective areas 122 and 121 (FIG. 2) of the mask 41. As the reflected light beams 34 and 37 advance to the right, the beams 34 and 37 are simultaneously vertically aligned with the respective apertures 42 and 43. Such simultaneous alignment produces the simultaneous pulses .46 and 47 which are simultaneously applied to the photosensitive detectors 48 and 49.

On the other hand, when the coils 1212 are spaced incorrectly, as illustrated in FIG. 3 by the coils 51 and 52 having the unacceptable pitch 53, the reflected light beams 54 and 55 do not pass simultaneously through the respective apertures 42 and 43. Rather, as the twistor wire 10 advances to the right, as viewed in FIG. 3, the reflected light beams 54 and 55 initially impinge upon the respective sections 121 and 122 of the mask 41. As the reflected beams 54 and 55 impinge on the mask 41, the reflected light beam 55 is spaced from the beam 54 by a distance greater than the spacing of the apertures 42 and 43. Thus, the beam 54 advances into vertical alignment with the aperture 42 before the beam 55 is vertically aligned with the aperture 43 so that the light pulse 58, representing the maximum amount :of light that the aperture 42 passes, is passed before the light pulses 59 formed when the beam 55 is aligned with the aperture 43.

The photodetectors 48 and 49 are mounted in the upper end 111 of the vertical section 112 of the housing 101 adjacent to the respective apertures 42 and 43. The photodetectors 48 and 49 may be standard detectors such as photoemissive cells, photoconductors, or phototransistors which generate electrical signals in response to a pulse of light. As shown in FIG. 2, in response to the simultaneous light pulses 46 and 47, the photodetectors 48 and 49 generate the simultaneous signals 44 and 45 which are efiective to render the monitoring circuit 28 ineflective to generate the error signal 61.

In responsive to the successive light pulses 58 and 59 (FIG. the pho-todetectors 48 and 49, respectively, generate the successive signals 56 and 57 which are applied by respective conductors 131 and 132 to respective amplifiers 134 and 136. The successive signals 56 and 57 are spaced by a phase difference 0 which is proportional to the diflerence between the nominal pitch 18 and the unacceptable pitch 53. The amplified signals 56 and 57 are applied to respective band-pass filters 141 and 142 which apply signals 143 and 144 having the phase difference 0 to respective amplifiers 151 and 152. The amplified signals 151 and 152 are applied to a phase detector 153 which generates the error signal 61 having an amplitude which is proportional to the phase diiference 0 between the signals 56 and 57, and a sign which indicates whether or not the signal 56 leads or lags the signal 57.

The error signal 61 operates a recorder 156 which indicates the amplitude and the sign of the error signal 61. Also, the error signal 61 is applied to the capstan control circuit 60. The capstan control circuit 60 includes a chopper amplifier 161 which applies the amplified error signal 61 to a control winding 162 of a servo resolver or twophase motor 165. A rotor 167 of the motor 165 is located in a rotary orientation according to the amplitude and sign of the error signal 61. The rotor 167 controls a potentiometer 169 of a control network 173 provided for controlling the electro-magnetic clutch 82. More particularly, when the error signal '61, generated in response to the successive signals 56 and 57, is applied to the motor 165, the rotor 167 rotates the potentiometer 171 to provide more resistance between a clutch power supply 181 and the clutch 82. With more resistance provided, less coupling is efiected by the clutch 82 between the capstan drive motor 81 and the capstan 83, so that the capstan 83 advances the twister wire 10 at a lower rate of speed.

With the rate of speed adjusted, the optical unit 26 senses a smaller error in the pitch 53 and causes a smaller error signal 61 to be generated and, hence, a smaller rate correction to be made until the nominal rate is achieved. At this time, the pitch of the coils 1212 equals the nominal pitch 18.

The optical sensing unit 26 senses the coils 12-12 having the nominal pitch 18 and causes the simultaneous pulses 46 and 47 to be applied to the respective photodetectors 48 and 49. No error signal 61 is generated by the monitoring circuit 28 in response to the simultaneous pulses 46 and 47, indicating that the twister-wire 10 is ad vancing at the nominal rate and is rendering the wrapping device 22 effective to wrap the coils 12-12 having the nominal pitch 18.

It should be noted that the pitch 18 of adjacent coils 1212 (FIG. 1) may be adjusted by changing the relative speeds of the advancement of carrier wire 11 and the application of coils 12-12 to the carrier wire. In the abovedescribed embodiment, such relative speeds are adjusted by changing the speed of carrier wire advancement (i.e., the speed of capstan 23). It should be clear that relative speed adjustment may also be accomplished by changing the speed of application of coils 12-12 to the carrier wire (i.e., the speed of Wrapping device 22), or by making a coordinated change in both speed of carrier wire advancement and of coil application.

In the above-described embodiment, light beams 32 were produced by reflection from coils 1212. It should be clear that beams indicative of the spacing of coils 1212 may also be produced by illuminating the coils from below to produce images or shadows of adjacent coils indicative of coil spacing. Detectors 48 and 49 would then sense spaced shadow beams rather than spaced reflected light beams to produce signals 26 and 27.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of this invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is: 1. An apparatus for applying reflective elements to a carrier member in a predetermined, spaced relationship, which comprises:

means for supplying said reflective elements to said carrier member at a constant rate;

means for advancing said carrier member at a variabl rate to permit said carrier member to receive acceptable reflective elements at acceptable intervals spaced by a first distance and unacceptable reflective elements at unacceptable intervals spaced by a second distance;

means for illuminating said reflective elements on said carrier member to reflect from said unacceptable reflective elements first and second beams spaced by said second distance;

blocking means for successively passing said first and second beams spaced by said second distance;

means responsive to said successively passed first and second beams for generating successive signals indicative of spacing of said unacceptable reflective elements by said second distance; and

means responsive to said successive signals for operating said advancing means at a selected speed to advance said carrier member at a given rate for reception of said reflective elements at said acceptable intervals.

2. Apparatus for providing an elongated carrier member with a helical serving having a desired pitch, which comprises:

means for longitudinally advancing the carrier member,

means for applying a serving about the advancing carrier member,

means for illuminating the serving to produce beams therefrom having spacing proportional to the pitch of the serving, and

means responsive to the spacing of the beams for adjusting the relative rates of the advancing and applying means to apply a serving upon the carrier member having the desired pitch.

3. Apparatus for applying a strand to an elongated member, which comprises:

means for wrapping said strand around said member;

means for advancing said member relative to said wrapping means to render said member receptive to coils of said strand spaced by a pitch distance, the value of said pitch distance bebing dependent upon the rate of advancement of said member relative to said wrapping means;

means for illuminating said coils to produce first and second beams spaced according to said pitch distance;

means for simultaneously passing said first and second beams spaced by a first distance and for successively passing said first and second beams spaced by a second distance; and

means responsive to said successively passed first and second light beams for regulating the relative rates of the wrapping and advancing means to adjust said pitch distance to a desired value.

4. Apparatus for controlling the pitch of coils of tape wrapped around an elongated member, which comprises: means for advancing said member along a path extending in a given direction;

means for wrapping said tape onto said advancing member to form said coils having a nominal pitch proportional to the rate of advancement of the member;

means for illuminating a pair of adjacent coils to produce parallel beams having a spacing indicative of the pitch of the adjacent coils;

a mask having a pair of spaced apertures therein, said apertures being spaced in said given direction to successively pass said beams from adjacent coils having an undesired pitch differing from said nominal pitch;

photoelectric means successively responsive to said successively passed beams for generating an error signal indicative of the difference between the nominal pitch and the undesired pitch; and

control means responsive to said error signal for regulating the relative speeds of said advancing and wrapping means to render said wrapping means eflective to form said coils having said nominal pitch.

5. A wrapping apparatus, which comprises:

a supply stand for feeding a wire in a given direction;

a wrapping head for wrapping coils of a tape onto said wire;

take-up means for taking up said wrapped wire at a selected rate, said selected rate governing the pitch of said coils on said wire;

a mask mounted adjacent to said wrapped wire, said mask having a pair of apertures therein spaced in a direction parallel to said given direction, the spacing between said apertures being proportional to a desired pitch of adjacent coils;

means for illuminating said wrapped wire to produce a pair of beams from said adjacent coils, said beams from said adjacent coils having an undesired pitch being passed through said apertures in succession;

photosensitive means responsive to said successively passed beams for generating an error signal indicative of the amount of deviation of said undesired pitch from said desired pitch; and

means responsive to said error signal for controlling the relative speeds of the take-up means and wrapping head to cause wrapping of coils having said desired pitch.

6. Apparatus for controlling the pitch of coils of tape wound onto a carrier wire, which comprises:

a serving head for wrapping said tape onto said carrier wire to form said coils, said serving head normally being effective to wrap said coils having a first pitch;

a light projector for illuminating the wrapped carrier wire to cause each coil of tape to produce a beam;

a mask having a pair of apertures, said apertures being spaced by a distance proportional to said first pitch;

capstan means for advancing said wrapped carrier wire, said advancement of said wrapped carrier wire relative to said mask causing said beams from adjacent coils having a second pitch different from said first pitch to scan said mask and pass in succession through said apertures;

photoelectric means responsive to said successively passed beams for generating an error signal; and

means responsive to said error signal for controlling the relative speeds of the advancing means and the serving head to render said serving head effective to wrap coils having said first pitch.

7. Apparatus for controlling the pitch of coils of tape wrapped around an elongated member, which comprises:

means for advancing said member at a variable rate of advancement along a path extending in a given direction;

means for wrapping said tape onto said advancing member to form said coils having a nominal pitch proportional to said variable rate of advancement;

means for illuminating a pair of adjacent coils to reflect therefrom parallel bands of light having a spacing indicative of the pitch of the adjacent coils;

a mask having a pair of spaced apertures therein, said apertures being spaced in said given direction to sucsively pass said parallel bands of light reflected from adjacent coils having an undesired pitch diflering from said nominal pitch;

photoelectric means successively responsive to said successively passed bands of light for generating an error signal indicative of the diflerence between the nominal pitch and the undesired pitch; and

control means responsive to said error signal for regulating the relative rates of the advancing and wrapping means to form coils on the elongated member having said nominal pitch.

8. An apparatus for controlling the speed of advancement of a carrier member having spaced, reflective elements thereon; acceptable, adjacent elements being spaced by a first distance and unacceptable, adjacent elements being spaced by a second distance; which comprises:

means for illuminating said reflective elements to reflect from said unacceptable reflective elements first and second light beams spaced by a distance proportional to said second distance,

blocking means for selecting beams spaced by a distance proportional to said first distance,

means for advancing said carrier member at a variable 9 10 rate to render said blocking means effective to pass References Cited said first and second beams in succession, means responsive to said successively passed first and UNITED STATES PATENTS second beams for generating successive signals in- 2,760,137 8/1956 Andrews 24255.11 X dicative of spacing of said unacceptable reflective 5 3,155,221 11/1964 Grinner 250-223 X elements by said second distance, and 3,242,661 3/ 1966 Siler 57-3 X means responsive to said successive signals for regulating said advancing means to adjust the rate of FRANK L COHEN Primary Examiner advancement of said carrier member to a selected rate. 10 A. J. SIDOTI, Assistant Examiner. 

3. APPARATUS FOR APPLYING A STRAND TO AN ELONGATED MEMBER, WHICH COMPRISES: MEANS FOR WRAPPING SAID STRAND AROUND SAID MEMBER; MEANS FOR ADVANCING SAID MEMBER RELATIVE TO SAID WRAPPING MEANS TO RENDER SAID MEMBER RECEPTIVE TO COILS OF SAID STRAND SPACED BY A PITCH DISTANCE, THE VALUE OF SAID PITCH DISTANCE BEDING DEPENDENT UPON THE RATE OF ADVANCEMENT OF SAID MEMBER RELATIVE TO SAID WRAPPING MEANS; MEANS FOR ILLUMINATING SAID COILS TO PRODUCE FIRST AND SECOND BEAMS SPACED ACCORDING TO SAID PITCH DISTANCE; MEANS FOR SIMULTANEOUSLY PASSING SAID FIRST AND SECOND BEAMS SPACED BY A FIRST DISTANCE AND FOR SUCCESIVELY PASSING SAID FIRST AND SECOND BEAMS SPACED BY A SECOND DISTANCE; AND MEANS RESPONSIVE TO SAID SUCCESSIVELY PASSED FIRST AND SECOND LIGHT BEAMS FOR REGULATING THE RELATIVE RATES OF THE WRAPPING AND ADVANCING MEANS TO ADJUST SAID PITCH DISTANCE TO A DESIRED VALUE. 